The initial training procedures as well as subsequent proficiency determinations which have evolved in connection with the instruction of pilots provides for the carrying out of a variety of defined aircraft maneuvers. Such maneuvers, for example, will include stalls, steep turns, climbs, descents, and the like and, in accordance with F.A.A. regulations, each of these airborne maneuvers must be carried out in conjunction with visual outside references (VFR) as well as solely by reference to instruments, (IFR). See F.A.A. regulation 61.43. To obtain or maintain instrument certification, instrument flight time generally is logged under airborne flight conditions wherein the individual under training utilizes equipment which excludes any visual reference outside of the aircraft. See F.A.A. Regulation 61.45(d), 61.51(c)(4).
To provide airborne simulation of conditions wherein outside references are blocked to the pilot's vision, several implementations have been utilized. One approach has been to provide an opaque canopy which covers the pilot's head, thus permitting only an observation by the pilot of controls and instruments within the cockpit, extended observation of the flight region exterior to the aircraft being availed only to an instructor or safety pilot attending the individual in training.
Another technique implementing such training has been to utilize a blue-yellow chromatic screening technique wherein, for example, a blue transparent polymeric material is positioned against the windscreen of the aircraft, while the pilot under instruction wears yellow tinted glasses. As a consequence, the vision of the pilot under instruction is blocked only with respect to the region or world outside of the cockpit, while the instructor or safety pilot may observe that outside world, albeit in a tinted fashion. Such an arrangement, however, has been found to be unsafe and has fallen from use.
Still another widely used technique involves the use of a plastic hood type device which is positioned upon the head of the pilot under instruction and is shaped generally in the form of a vision-directing half-tube extending from the face of that pilot about 6 inches and is pivotal downwardly to an extent where all peripheral and forward vision is fully blocked except for the instrumentation within the cockpit. Some versions of this device have a shorter forwardly extending tube, however, both embodiments present a hazzard during the airborne training sessions, inasmuch as the vision of the instructor or safety pilot is somewhat blocked by the rather bulksome and forwardly extending device. As a further aspect of these devices, they are somewhat expensive and are often misplaced and lost by both student pilots as well as instructors, usually being inadvertently left in the aircraft following training inasmuch as they cannot be stored conveniently in a pocket or the like. The amount of use of the devices, however, is somewhat extensive, 40 hours of flight time being required to develop instrument flying proficiency and a recurring requirement for proficiency of 6 hours of instrument flight time often times with the devices being necessitated thereafter. Thus, periods of aircraft operation in and about airfields and the like using these devices which may pose hazards are quite significant. Another disadvantage which has developed in connection with the canopy and tube type device resides in the claustrophobic effect which they have on the student pilot. In particular, the student is required to look with constrained vision under an elongate half-tube. This is not the actual flying condition encountered during non-simulated instrument flight and thus, does not evoke the desired close simulation of actual adverse flight conditions.
Another aspect of aircraft operation under conditions of occluded vision involves adverse weather flying. Pilots are provided extensive weather analysis prior to take-off and by radio communication during flight. However, the extent of airborne training with respect to airborne encountered weather is minimal at best, and the importance of pilot competencey under adverse weather conditions becomes manifest considering that 30 percent of all fatal aircraft incidences result from adverse weather. Of compelling importance, aircraft pilots should retain a capability to make competent judgement as to when to turn around in the face of weather (particularly in the face of hard-to-judge visibility restrictions) and return to base; to proceed to alternate airports; or solicit help by radio from ground based stations.